Vapor-rectifier.



D. C. DAVIS.

VAPOR RECTIFIER.

APPLICATION FILED MAY H. 3914.

1,15,01 7. I "a Patented Aug. 17, 1915.

ATTORNEY DAVID C. DAVIS, 0F SWISSVALE, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A. CORPORATION OF PENNSYL- VANIA.

VAPOR-RECTIFIER.

Specification of Letters Patent.

Patented Aug. 1'7, 1915.

Application filed may 11, 1914. Serial No. 837,724.

To all whom it may concern Be it known that 1, DAVID C. DAVIS, a citizen of the United States, and a resident of Swissvale, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Vapor- Rectifiers, of which the following is a specification.

My invention relates to vapor electric apparatus of the type employed for lamps and rectifiers and it has for its object to provide a device of the character specified wherein the current required for the maintenance of the cathode activity will be produced Within the container. By my construction, I provide a rectifier which is self-starting and which has no keep-alive circuit sealed through the walls thereof, with attendant liability to leakage.

In the accompanying drawing, the single figure is a diagrammatic View, partially in section and partially in elevation, of a rectifier and its attendant circuits embodying my invention.

An evacuated container 1 of any suitable material, such, for example, as steel, is provided with two main anodes 2 and 3 and with a cathode 4. The cathode 4 is made of any suitable reconstructing material such, for example, as mercury. The terminals of a source 5 of alternating currents are con nected to the anodes 2 and 3 and a connection 5 from the container wall serves to carry rectified current to the load 6 from whence it is returned to the mid point of the source 5, as is well known in the art.

In the operation of vapor arc rectifiers of the type specified, there is a high inherent resistance to the flow of. current at or near the surface of the cathode, and it is necessary, in order to start the rectifier into operation, to break down this cathode reluctance and furthermore, it is necessary to maintain it in a broken-down condition so long as the rectifier is in operation. Hitherto, it has been the common practice to insert an auxiliary anode through the wall of the container and to maintain a direct-cur-.

rent are between the auxiliary anode and the main cathode. This method of maintaining the cathode activity is troublesome and expensive since it necessitates the employment of a separate source of direct current and also because it is necessary to provlde a joint between the auxiliary anode and the wall of the container which will be gas tight, insulating, and, at the same time, susceptible of wide temperature variation. By my invention, I do away with these disadvantages, induce a maintaining current entirely within the container and derive the energy for this induced current; directly from the alternating current supply.

A cup shaped member 7 of non-magnetic material, such, for example, as iron-nickel alloy, is welded to the edge of an opening in the bottom of the container, as shown at 88. A winding 9 is placed upon the exterior of the cup 7 and is connected to the terminals of the source 5 by means of wires 10-10, preferably through a phase-displacing device, such, for example, as a condenser 11. A cup shaped member 12 is placed over the winding 9 and engages the wall of the container 1 in any suitable manner, such, for example, as by a threaded flange 13. Within the member 7 is placed a winding 14 mounted upon a core member 15 of magnetic material and having a flat head 16, the edge of which is adjacent to the edge of the container wall. The winding 14 and its attendant core 15 are totally incased by a gas-tight wall 17, preferably of glass in order that the occluded gases within the winding shall be confined thereto. A hollow extension 18 of the casing wall 17 projects upwardly through the material of the cathode 4 and carries, near its upper end, two small electrodes 19 and 20 that are connected, respectively, to the two terminals of the winding 11 by means of wires 21 carried within the hollow member 18 and sealed through the wall thereof in any suitable manner, such, for example, as the ordinary platinum seal. A disk shaped member 22 surrounds the member 18 and floats in the material of the cathode, being entirely free to move in a vertical direction. Two small cup shaped members 23 and 24 are mounted on the upper surface of the member 22 and are adapted to coact, respectively, with two high-resistance filaments 25 and 26, depending from the electrodes 19 and 20. The midpoint of the winding H is connected to the material of the cathode by a wire 27 and a ring 28.

The operation of my device is as follows: Upon supplying current to the rectifier from the source 5, flow will take place through the winding 9 and the condenser 11. Owing to the nearly closed magnetic circuit provided by the member 12, the core 15 and the wall of the container at 29, alternating current will be induced in the winding 14 and will flow to the electrodes 19 and 20, through the filaments 25 and 26, cups 23 and 24 to the cathode 4 and thence to the mid point of the secondary winding 14: by the wire 27 Simultaneously with this action, the member 22 will be drawn down into the magnetic circuit and rest against the upper surface of the casing 17, entirely submerging the cups 23 and 2a and breaking the circuit between the filaments 25 and 26 and the mercury in' the cups. At the instant of break, one of the cups will be negative with respect to its attendant anode and the mercury therein will have its negative electrode reluctance broken down. In the succeeding half wave of the induced current from the winding 14, current will flow from the other small anode to the cup wherein the negative electrode reluctance is broken down. There will be practically no subsequent current flow in the filaments 25 and 26 since, as is Well known in the art, a small initial arc discharge from the point of high-resistance filament will immediately extend itself along the filament in order to take up low-resistance path. The rectification of the induced secondary current from the winding 14 to one of the cups having been initiated, the cup is submerged in the body of the electrode 4 by the movement of the member 22, and the mercury in the cup coalesces with that of the. main.

cathode and the cathode activity is transferred to the latter.- Under these conditions, the main anodes 2 and 3 come into action, and current is delivered to the load 6. By the use of the phase-displacing means 11, the time of maximum current flow from the anodes 19 and 20 may be made nearly coincident with the time of minimumfiow from the anodes 2 and 3, thus insuring ample current at all times for the proper maintenance activity.

Obviously, the cup shaped member 7 may extend inwardly rather than outwardly to carry the primary winding within itself and have the secondary winding mounted upon its exterior surface without departing from the spirit and scope of my invention. Furthermore, it is obvious that the entire confor inducing alternating current within the container, and means for rectifying the induced current, also within the container.

3. The combination with an evacuated container, of a complete electric circuit therein comprising a source of alternating current, means for rectifying the alternating current, and means for returning the rectified current to the source of alternating current.

4:. The combination with vapor electric apparatus comprising an evacuated container, an anode and a reconstructing cathode, of a source of alternating current within the container, an auxiliary anode connected to each terminal of said source, said auxiliary anodes being placed in operative relation to the reconstructing cathode, and a connection from the cathode to a point in the alternating current source.

' 5. The combination with vapor electric apparatus comprising an evacuated container, an anode and a reconstructing cathode, of a winding on the exterior of the container, a winding withinthe container in inductive relation thereto, an auxiliary anode connected to each terminal of the winding within the container and placed in operative relation to the reconstructing cathode, and a connection from the cathode to an intermediate point in the winding within the container.

6. The combination with vapor electric apparatus comprising an evacuated container, an anode and a reconstructing cathode, of means for applying an alternating electromotive force between the anode and the cathode, a Winding on the exterior of the container, means for supplying alternating current thereto, a Winding within an auxiliary anode connected to each terminal of the interior winding, said anodes being placed in operative relation to thereconstructing cathode, and a connection from the reconstructing cathode to an intermediate point on the interior Winding, Whereby alternating current is induced within the container and is rectified at the surface of the cathode, the negative electrode reluctance is continuously broken down and a main rectifying arc is enabled to flow within the device.

7. Maintaining means for a vapor rectifier having a metallic container comprising a cup shaped member of non-magnetic material having its rim sealed to the edge of an opening in the wall of the container, a primary winding mounted upon the exterior of said cup, a secondary winding mounted within the cup, an auxiliary anode connected to each terminal of the secondary winding, said auxiliary anodes being placed in operative relation to the main cathode of the rectifier, a connection from the main cathode to substantially the mid point of the secondary winding, and means for supplying alternating current to the primary winding, whereby alternating current is induced in the secondary winding, said alternating current is rectified at the surface of the cathode and returned to the secondary winding through the cathode, and a cathode spot is maintained on the surface of the cathode.

8. Maintaining means for a vapor rectifier having a metallic container comprising a cup of non-magnetic material having its rim sealed to the edge of an opening in the container wall, a primary winding on the exterior of said cup, a secondary Winding within the cup, means for supplying alternating current to the primary winding, and means whereby the current induced in the secondary winding maintains the interior of the container in a conducting condition.

9. Means for generating current within a closed container comprising a cup of nonmagnetic material having its rim sealed to the edge of an opening in the wall of the container, a primary Winding mounted on the exterior of the cup, a secondary winding within the cup, a mushroom shaped core of magnetic material having its stem within the secondary winding, and a cup of magnetic material covering the primary winding.

10. Means for generating current within a closed container comprising a cup of nonmagnetic material having its rim sealed to the edge of an opening in the wall of the container, a primary winding mounted on the exterior of the cup, a secondary windingwithin the cup, a mushroom shaped core of magnetic material having its stem within the secondary winding, a cup of magnetic material covering the primary winding, and

a vitreous casing sealed over the secondary winding and its core.

11. Starting and maintaining means for a vapor arc rectifier comprising a cup of nonmagnetic material having its rim sealed to the edge of an opening in the wall of the container, a primary winding mounted on the exterior of the cup, a secondary winding within the cup, a movable armature within the container, means whereby the passage of alternating current through the primary winding causes said armature to move into the magnetic circuit and by its movement break down the negative electrode reluctance of the rectifier, and means whereby the current induced in the secondary winding is rectified and maintains the activity of the cathode. 12. The combination with a vapor recti fier having an anode, a cathode, and a suitable source of alternating current, of a transformer having its primary winding outside and its secondary winding inside the container, means whereby the initial energization of the transformer starts the rectifier and the continued energization of the transformer maintains the rectifier in a conductive condition.

13. The combination with a vapor rectifier having a metallic casing and a reconstructing cathode therein, of a cup of nonmagnetic material having its rim sealed to the edge of an opening in the bottom of the container, a primary winding on the outside of said cup, a secondary winding inside said cup, a core of magnetic material within said secondary winding, a member of insulating material projecting upwardlyfrom said cup through the material of the cathode, a pair of anodes carried by said member above the surface of the cathode, each anode being connected to a terminal of the. secondary winding, a connection from the cathode to an intermediate point of said secondary winding, an armature of magnetic material in the cathode adjacent said anodes, and means whereby the passage of current through the primary winding and the consequent movement of the armature breaks down the negative electrode reluctance and the subsequent rectification of the induced current in the secondary Winding maintains the cathode in an operative condition.

14. The combination with a vapor rectifier having a metallic casing and a reconstructing cathode therein, of a cup of nonmagnetic material having its rim sealed to the edge of an opening in the bottom of the container, a primary winding on the outside of said cup, a secondary winding inside said cup, a core of magnetic material within said secondary winding, a member of insulating material projecting upwardly from said cup through the material of the cathode, a pair of anodes carried by said member above the surface of the cathode and a highresistance filament depending from each anode, each anode being connected to a terminal of the secondary winding, a connection from the cathode to an intermediate point of said secondary winding, .an armature of magnetic material in the cathode adjacent to said anodes and a pair of mercurycontaining cups carried on the upper surface of said armature and making contact with the lower ends of said filaments, whereby the energization of said primary wind- In testimony whereof, I have hereunto ing causes current to be induced'in the secsubscribed my name this 28th day of April, ondary winding and causes the armature to 1914.

be drawn to the bottom of the cathode, the DAVID c. DAVIS. 5 circuit-to be broken at the end of each fila- Witnesses:

ment and the rectification of the secondary B. B. HINES,

current to be initiated. M. C. MERZ. 

